scholarly journals δ-Tocotrienol, Isolated from Rice Bran, Exerts an Anti-Inflammatory Effect via MAPKs and PPARs Signaling Pathways in Lipopolysaccharide-Stimulated Macrophages

2018 ◽  
Vol 19 (10) ◽  
pp. 3022 ◽  
Author(s):  
Junjun Shen ◽  
Tao Yang ◽  
Youzhi Xu ◽  
Yi Luo ◽  
Xinyue Zhong ◽  
...  

δ-Tocotrienol, an important component of vitamin E, has been reported to possess some physiological functions, such as anticancer and anti-inflammation, however their molecular mechanisms are not clear. In this study, δ-tocotrienol was isolated and purified from rice bran. The anti-inflammatory effect and mechanism of δ-tocotrienol against lipopolysaccharides (LPS) activated pro-inflammatory mediator expressions in RAW264.7 cells were investigated. Results showed that δ-tocotrienol significantly inhibited LPS-stimulated nitric oxide (NO) and proinflammatory cytokine (TNF-α, IFN-γ, IL-1β and IL-6) production and blocked the phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular regulated protein kinases 1/2 (ERK1/2). δ-Tocotrienol repressed the transcriptional activations and translocations of nuclear factor-kappa B (NF-κB) and activator protein-1 (AP-1), which were closely related with downregulated cytokine expressions. Meanwhile, δ-tocotrienol also affected the PPAR signal pathway and exerted an anti-inflammatory effect. Taken together, our data showed that δ-tocotrienol inhibited inflammation via mitogen-activated protein kinase (MAPK) and peroxisome proliferator-activated receptor (PPAR) signalings in LPS-stimulated macrophages.

PPAR Research ◽  
2008 ◽  
Vol 2008 ◽  
pp. 1-16 ◽  
Author(s):  
Elke Burgermeister ◽  
Rony Seger

Peroxisome proliferator-activated receptor-gamma (PPARγ) exerts multiple functions in determination of cell fate, tissue metabolism, and host immunity. Two synthetic PPARγligands (rosiglitazone and pioglitazone) were approved for the therapy of type-2 diabetes mellitus and are expected to serve as novel cures for inflammatory diseases and cancer. However, PPARγand its ligands exhibit a janus-face behaviour as tumor modulators in various systems, resulting in either tumor suppression or tumor promotion. This may be in part due to signaling crosstalk to the mitogen-activated protein kinase (MAPK) cascades. The genomic activity of PPARγis modulated, in addition to ligand binding, by phosphorylation of a serine residue by MAPKs, such as extracellular signal-regulated protein kinases-1/2 (ERK-1/2), or by nucleocytoplasmic compartmentalization through the ERK activators MAPK kinases-1/2 (MEK-1/2). PPARγligands themselves activate the ERK cascade through nongenomic and often PPARγ-independent signaling. In the current review, we discuss the molecular mechanisms and physiological implications of the crosstalk of PPARγwith MEK-ERK signaling and its potential as a novel drug target for cancer therapy in patients.


Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 386 ◽  
Author(s):  
Yufeng Cao ◽  
Fu Li ◽  
Yanyan Luo ◽  
Liang Zhang ◽  
Shuya Lu ◽  
...  

20-Hydroxy-3-oxolupan-28-oic acid (HOA), a lupane-type triterpene, was obtained from the leaves of Mahonia bealei, which is described in the Chinese Pharmacopeia as a remedy for inflammation and related diseases. The anti-inflammatory mechanisms of HOA, however, have not yet been fully elucidated. Therefore, the objective of this study was to characterize the molecular mechanisms of HOA in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. HOA suppressed the release of nitric oxide (NO), pro-inflammatory cytokine tumor necrosis factor α (TNF-α), and interleukin 6 (IL-6) in LPS-stimulated RAW264.7 macrophages without affecting cell viability. Quantitative real-time reverse-transcription polymerase chain reaction (RT-qPCR) analysis indicated that HOA also suppressed the gene expression of inducible NO synthase (iNOS), TNF-α, and IL-6. Further analyses demonstrated that HOA inhibited the phosphorylation of upstream signaling molecules, including p85, PDK1, Akt, IκBα, ERK, and JNK, as well as the nuclear translocation of nuclear factor κB (NF-κB) p65. Interestingly, HOA had no effect on the LPS-induced nuclear translocation of activator protein 1 (AP-1). Taken together, these results suggest that HOA inhibits the production of cytokine by downregulating iNOS, TNF-α, and IL-6 gene expression via the downregulation of phosphatidylinositol 3-kinase (PI3K)/Akt and mitogen-activated protein kinases (MAPKs), and the inhibition of NF-κB activation. Our findings indicate that HOA could potentially be used as an anti-inflammatory agent for medical use.


2022 ◽  
Author(s):  
Yiyi Hong ◽  
Li Jiang ◽  
Wei Huang ◽  
Wen Deng ◽  
Fen Tang ◽  
...  

Abstract Objective Based on recent reports, peroxisome proliferator-activated receptor-γ (PPAR-γ) could promote microglial M2 polarization to inhibit inflammation. However, the specific molecular mechanisms instigate the anti-inflammatory ability of PPAR-γ in microglia have not been expounded. In the present study, we explored the molecular mechanisms of the anti-inflammatory effects of PPAR-γ in hypoxia-stimulated rat microglial cells. Methods shRNA expressing lentivirus was used to knock down PPAR-γ and CD200 genes. The hypoxia-induced polarization markers release (M1: iNOS, IL-1β, IL-6 and TNF-α; M2: Arg-1, YM1, IL-4 and IL-10) was assessed by RT-PCR, while PPAR-γ-related signals (PPAR-γ, PPAR-γ in cytoplasm or nucleus, CD200 and CD200Rs) were monitored by western blot and RT-PCR. Results Hypoxia enhanced PPAR-γ and CD200 expressions in microglial cells. In addition, PPAR-γ agonist 15d-PGJ2 elevated CD200 and CD200R1 expressions, while sh-PPAR-γ (PPAR-γ knock-down) had just the opposite effect. Following hypoxia, expressions of M1 markers increased significantly, while those of M2 markers decreased, and the above effects were attenuated by 15d-PGJ2. Conversely, knocking down PPAR-γ or CD200 inhibited the polarization of microglial cells to M2 phenotype. Conclusion Results demonstrated that PPAR-γ performed an anti-inflammatory function in hypoxia-stimulated microglial cells by promoting their polarization to M2 phenotype via CD200-CD200R1 pathway.


Author(s):  
Roya Kazemi ◽  
Seyed Jalal Hosseinimehr

Objective: Pioglitazone (PG) is used to control high blood sugar in patients with type 2 diabetes mellitus. PG acts as a peroxisome proliferator-activated receptor γ agonist. In addition to the insulin-sensitizing effect, PG possesses anti-inflammatory effect. In this study, the protective effect of PG was evaluated against DNA damage induced by ionizing radiation in human healthy lymphocytes. Methods: The microtubes containing human whole blood were treated with PG at various concentrations (1-50 μM) for three hours. Then, the blood samples were irradiated with X-ray. Lymphocytes were cultured for determining the frequency of micronuclei as a genotoxicity biomarker in binucleated lymphocytes. Results: The mean percentage of micronuclei was significantly increased in human lymphocytes when were exposed to IR, while it was decreased in lymphocytes pre-treated with PG. The maximum reduction in the frequency of micronuclei in irradiated lymphocytes was observed at 5 μM of PG treatment (48% decrease). Conclusion: The anti-inflammatory property is suggested the mechanism action of PG for protection human lymphocytes against genotoxicity induced by ionizing radiation.


2017 ◽  
Vol 43 (2) ◽  
pp. 540-552 ◽  
Author(s):  
Hany H. Arab ◽  
Samir A. Salama ◽  
Tamer M. Abdelghany ◽  
Hany A. Omar ◽  
El-Shaimaa A. Arafa ◽  
...  

Background/Aims: Camel milk (CM) has shown beneficial anti-inflammatory actions in several experimental and clinical settings. So far, its effect on rheumatoid arthritis (RA) has not been previously explored. Thus, the current work aimed to evaluate the effects of CM in Adjuvant-induced arthritis and air pouch edema models in rats, which mimic human RA. Methods: CM was administered at 10 ml/kg orally for 3 weeks starting on the day of Freund’s adjuvant paw inoculation. The levels of TNF-α and IL-10 were measured by ELISA while the protein expression of NF-κBp65, COX-2 and iNOS was detected by immunohistochemistry. The expression of MAPK target proteins was assessed by Western blotting. Results: CM attenuated paw edema, arthritic index and gait score along with dorsal pouch inflammatory cell migration. CM lowered the TNF-α and augmented the anti-inflammatory IL-10 levels in sera and exudates of arthritic rats. It also attenuated the expression of activated NF-κBp65, COX-2 and iNOS in the lining of the dorsal pouch. Notably, CM inhibited the MAPK pathway signal transduction via lowering the phosphorylation of p38 MAPK, ERK1/2 and JNK1/2 in rat hind paws. Additionally, CM administration lowered the lipid peroxide and nitric oxide levels and boosted glutathione and total anti-oxidant capacity in sera and exudates of animals. Conclusion: The observed CM downregulation of the arthritic process may support the interest of CM consumption as an adjunct approach for the management of RA.


Marine Drugs ◽  
2020 ◽  
Vol 18 (4) ◽  
pp. 222 ◽  
Author(s):  
Wenhui Jin ◽  
Longhe Yang ◽  
Zhiwei Yi ◽  
Hua Fang ◽  
Weizhu Chen ◽  
...  

Palmitoylethanolamide (PEA) is an endogenous lipid mediator with powerful anti-inflammatory and analgesic functions. PEA can be hydrolyzed by a lysosomal enzyme N-acylethanolamine acid amidase (NAAA), which is highly expressed in macrophages and other immune cells. The pharmacological inhibition of NAAA activity is a potential therapeutic strategy for inflammation-related diseases. Fucoxanthinol (FXOH) is a marine carotenoid from brown seaweeds with various beneficial effects. However, the anti-inflammatory effects and mechanism of action of FXOH in lipopolysaccharide (LPS)-stimulated macrophages remain unclear. This study aimed to explore the role of FXOH in the NAAA–PEA pathway and the anti-inflammatory effects based on this mechanism. In vitro results showed that FXOH can directly bind to the active site of NAAA protein and specifically inhibit the activity of NAAA enzyme. In an LPS-induced inflammatory model in macrophages, FXOH pretreatment significantly reversed the LPS-induced downregulation of PEA levels. FXOH also substantially attenuated the mRNA expression of inflammatory factors, including inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), and markedly reduced the production of TNF-α, IL-6, IL-1β, and nitric oxide (NO). Moreover, the inhibitory effect of FXOH on NO induction was significantly abolished by the peroxisome proliferator-activated receptor α (PPAR-α) inhibitor GW6471. All these findings demonstrated that FXOH can prevent LPS-induced inflammation in macrophages, and its mechanisms may be associated with the regulation of the NAAA-PEA-PPAR-α pathway.


2020 ◽  
Vol 21 (19) ◽  
pp. 7247
Author(s):  
Jyun-Bin Huang ◽  
Shih-Pin Hsu ◽  
Hsiu-Yung Pan ◽  
Shang-Der Chen ◽  
Shu-Fang Chen ◽  
...  

Status epilepticus may cause molecular and cellular events, leading to hippocampal neuronal cell death. Peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α) is an important regulator of vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR2), also known as fetal liver kinase receptor 1 (Flk-1). Resveratrol is an activator of PGC-1α. It has been suggested to provide neuroprotective effects in epilepsy, stroke, and neurodegenerative diseases. In the present study, we used microinjection of kainic acid into the left hippocampal CA3 region in Sprague Dawley rats to induce bilateral prolonged seizure activity. Upregulating the PGC-1α pathway will increase VEGF/VEGFR2 (Flk-1) signaling and further activate some survival signaling that includes the mitogen activated protein kinase kinase (MEK)/mitogen activated protein kinase (ERK) and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathways and offer neuroprotection as a consequence of apoptosis in the hippocampal neurons following status epilepticus. Otherwise, downregulation of PGC-1α by siRNA against pgc-1α will inhibit VEGF/VEGFR2 (Flk-1) signaling and suppress pro-survival PI3K/AKT and MEK/ERK pathways that are also accompanied by hippocampal CA3 neuronal cell apoptosis. These results may indicate that the PGC-1α induced VEGF/VEGFR2 pathway may trigger the neuronal survival signaling, and the PI3K/AKT and MEK/ERK signaling pathways. Thus, the axis of PGC-1α/VEGF/VEGFR2 (Flk-1) and the triggering of downstream PI3K/AKT and MEK/ERK signaling could be considered an endogenous neuroprotective effect against apoptosis in the hippocampus following status epilepticus.


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